Both terms mean the same thing. The verb "switch" is the counterpart of the noun "switch." A switch is a generic device that diverts the flow of something, in this example electricity, from one path to another, or "on" or "off."

Switches take a number of forms, one of which is rotary; that is, electrical current can be diverted from one path to another, or "on" or "off," by rotating a knob. Other forms are toggle, which can assume either of two lateral positions by being flipped, and push-button, which can assume either of two alternate conditions by being pushed into its mounting.

The difference between the two verbs in question is that "turn off" describes the action of turning the knob of a rotary switch from the "on" to the "off" position, thereby stopping the flow of electrical current, while "switch off" describes the action of using any switch, whether rotary, toggle, or push-button, to stop the flow of current.

Gineva Kingsley

ex-grammar Nazi, gave up on correcting people after the internet was invented

Both mean similar things, and sometimes people use it interchangably, but if you reaaaaaaallly wanted to get technically about it, you turn off things with buttons and you switch off things with switches. Switches are not buttons and buttons are not switches.

That’s a switch, this is a button:

Pedro Chopite

Over 50 years using words

When referring to things, the two are synonyms:

switch (something) off or switch off (something) : to turn off (something) by turning or pushing a button or moving a switch, lever, etc.

turn off (something) or turn (something) off : to stop the operation or flow of (something) by pressing a button, moving a switch, etc.

He switched off the light/lamp.

She turned off the alarm/heat/lights/water.

Should I leave the TV on or turn it off?

When referring to people, they have different meanings:

turn (someone) off or turn off (someone) informal : to cause a strong feeling of dislike in (someone) : to be unappealing to (someone)

People who smoke turn me off.

switch off informal : to stop paying attention

When the topic turned to the stock market, he switched off. [=tuned out]

Frank Elliott

Writer

In a general, practical sense, no difference. Each of:

turn off,

switch off,

shut off,

cut off, or

extinguish (rare)

an electric light/device/appliance means to interrupt its electrical power circuit (as is commonly done using a power or on/off switch), thereby disconnecting it from its electrical current source—rendering it inactive or inoperative.

In each case above except for cut off and shut off, it's generally okay to also change off to on (and some speakers may say cut on—but shutor cut on is nonsensical).

Bistappayya Nadiger

A grammar police.

Generally both means the same. Both are phrasal verbs . When you hold a battery in your hand , you may say ‘turn off or ‘switch off’. Both mean the same . Similarly ‘turn on’ and ‘switch on’ are equal in meaning.

But if you go deep , we find there exists the little.

When you are holding a pipe in your hand, to cut the water flow, you can say ,’turn off’ and to run the water flow ‘turn on’ : here you can not say ‘switch on’ and switch off’ . ‘switch off’ is used to cut off the electric current flow.

Manoj Sharma

Bibliophile, curious, a teacher.

Turn off (not to get confused with turn-off)- stop the function of (a stove, a water faucet, a car, etc.)

Sentence: Don't forget to turn off the iron before you leave the house.

Switch off: to stop giving your attention to someone of something, to cause (a device) to stop operating by or as if by moving a switch, knob, or lever.

Sentence: please switch off the fan.

Whenever I get bored, I simply switch off and watch out of the window.